The invention relates to a transmission for a motor vehicle, in particular a twin-clutch manual transmission.
In such known transmissions, for changing gears the rotary speeds of the members to be shifted are made to match one another by means of a synchronizing device, which as a rule has synchronizing rings. Furthermore, for starting the internal combustion engine of the motor vehicle, a separate starter is provided, which when the clutches are disengaged rotates the crankshaft of the engine. The engine is supplied with energy by the battery of the motor vehicle, which in turn is charged constantly by a generator. The known transmission and hence the motor vehicle thus require a number of coordinate devices for its operation, and the synchronizing devices are more or less complex in design.
The transmission of the invention for a motor vehicle, in particular a twin-clutch manual transmission has the advantage over the prior art that because of the electric machine coupled to the at least one input shaft, a starter and a generator for the engine can be dispensed with. Furthermore, easy synchronization of the members to be shifted of the various gears is possible without additional synchronizing devices.
A relatively small size of the electric machines is necessary if each of the two input shafts is equipped with a separate electric machine. Furthermore, in that case a relatively simple coupling to the input shafts can be attained. By comparison, if a distributor transmission is used, it is possible to employ merely a single electric machine, which can be coupled to one or the other of the input shafts.
Operating a motor vehicle with a transmission of the invention has the particular advantage that in the overrunning mode of the motor vehicle, the rolling energy of the vehicle can be converted into electrical energy that charges the on-board battery, if the electric machine or electric machines function as generators in the overrunning mode. It is also possible, for driving the motor vehicle in reverse, to dispense with a corresponding gear wheel set in the transmission, if an electric machine drives a forward gear in reverse.
It is also possible to use the electric machine or electric machines as an additional drive mechanism which reinforces the engine, so that greater total power can be furnished briefly, for instance during passing.